MRS1845 is a selective store-operated calcium ( SOC ) channel inhibitor with an IC 50 of 1.7 μM. MRS1845 is an ORAI1 inhibitor . MRS1845 is a click chemistry reagent, it contains an Alkyne group and can undergo copper-catalyzed azide-alkyne cycloaddition (CuAAc) with molecules containing Azide groups.